The present disclosure relates generally to information handling systems, and more particularly to transmitting multicast communications between information handling systems across different datacenters.
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems such as, for example, server devices, storage devices, switch devices, router devices, and/or other computing devices are often provided in datacenters. It is sometimes desirable for information handling systems in different datacenters to communicate, and often those information handling systems may be provided as part of the same Virtual Local Area Network (VLAN) in order to facilitate that communication, which may be performed over a Layer 3 (L3) network (e.g., the Internet) and/or a Layer 2 (L2) network that are provided between the datacenters. One example of such datacenters provides router devices in the datacenters that interface with both the L3 network (which is connected to the peer datacenter(s)), as well as a Layer 2 (L2) network within their respective datacenter. That L2 network may be provided by the router devices, Top Of Rack (TOR) switch devices connected to the router devices, and server devices connected to the TOR switch devices.
In a specific example, the router devices, TOR switch devices, and server devices may be connected via Multi-chassis Link Aggregation Groups (MLAGs), with the router devices connected via Virtual Link Trunking (VLT) (an aggregation protocol available from Dell Inc. of Round Rock, Tex., United States). Each server device may provide (or “host”) virtual machines that may be migrated within a datacenter and across the datacenters using a variety of virtual machine migration techniques (or container deployment instantiation techniques) known in the art. Those virtual machine may act as data communication sources (“source virtual machines”) and/or data communication receivers (“receiver virtual machines”), and often the receiver virtual machines may belong to Protocol Independent Multicast-Sparse Mode (PIM-SM) or Protocol Independent Multicast-Secure Specific Multicast (PIM-SSM) multicast trees that are provided across the multiple datacenters. As such, a VLAN may include virtual machines in different datacenters, resulting in an L2 network domain spanning across those different datacenters, which can cause some issues.
In such multi-datacenter systems, the first hop router device/designated router device (“FHR/DR device”) for a source virtual machine that is provided on a server device may be relatively remote from that server device. For example, a source virtual machine provided on a server device in a first datacenter may have a FHR/DR device in a second datacenter, and that FHR/DR device may also be a last hop router/designated router device (“LHR/DR device”) for a receiver virtual machine is also provided by a server device in the first datacenter. In such a scenario, data communication from the source virtual machine will be sent out of the first datacenter and to the FHR/DR device-LHR/DR device in the second datacenter, and then forwarded by the FHR/DR device-LHR/DR device back to the receiver virtual machine in the first datacenter. As such, the data communications from the source virtual machine to the receiver virtual machine will traverse the inter-datacenter links in the L2 network twice in a phenomenon called “traffic tromboning”, which increases the latency associated with the data traffic, as well as the traffic load on the MLAGs provided in the L2 network between the datacenters.
Furthermore, in addition to traffic tromboning, multi-datacenter systems often provide multiple copies of the same data communication across the inter-datacenter links in the L2 network. For example, a source virtual machine that is provided by a server device in a first datacenter and that is part of a first VLAN may have a FHR/DR device in the first datacenter. That FHR/DR device may include a multicast route with the first VLAN as an incoming interface, and multiple VLANs as the outgoing interface, with those multiple VLANs including receiver virtual machines that are provided by server device(s) in a second datacenter. When the FHR/DR device is also a LHR/DR device for the receiver virtual machines, a multicast communication sent by the source virtual machine and received by the FHR/DR device-LHR/DR/RP device in the first datacenter will be replicated for each VLAN including a receiver virtual machine, and those replicated communications are then sent over the MLAGs provided in the L2 network to the second datacenter so that each replicated communication may be provided to those receiver virtual machines. As such, multicast communications in multi-datacenter systems can greatly increase the amount of communications sent via inter-datacenter communication links.
Accordingly, it would be desirable to provide an improved inter-datacenter multicast system.